Mengapa stainless steel double-sided countersunk head blind rivets semi-stainless steel?

Amarga kabeh mandrel ditarik metu sawise keling wuta sirah countersunk pindho sisi riveted, materi mandrel ora mengaruhi resistance karat saka stainless steel pindho sisi countersunk sirah keling wuta.Kajaba iku, stainless steel luwih larang tinimbang wesi.Kanggo ngirit biaya, inti kuku digawe saka wesi.